A23975. 下面递归实现的斐波那契数列的时间复杂度为O(2n) 。（ ）def fib_memo(n, memo): if n <= 1: return n if memo[n] != -1: return memo[n] memo[n] = fib_memo(n - 1, memo) + fib_memo(n - 2, memo) return memo[n] if __name__ == "__main…

下面递归实现的斐波那契数列的时间复杂度为O(2ⁿ) 。（    ）

def fib_memo(n, memo):
    if n <= 1:
        return n
    if memo[n] != -1:
        return memo[n]
    memo[n] = fib_memo(n - 1, memo) + fib_memo(n - 2, memo)
    return memo[n]

if __name__ == "__main__":
    n = 40
    memo = [-1] * 100
    result = fib_memo(n, memo)
    print(result)